Effects of fluorinated solvents on electrolyte solvation structures and electrode/electrolyte interphases for lithium metal batteries

Electrolyte is very critical to the performance of the high-voltage lithium (Li) metal battery (LMB), which is one of the most attractive candidates for the next-generation high-density energy-storage systems. Electrolyte formulation and structure determine the physical properties of the electrolytes and their interfacial chemistries on the electrode surfaces. Localized high-concentration electrolytes (LHCEs) outperform state-of-the-art carbonate electrolytes in many aspects in LMBs due to their unique solvation structures. Types of fluorinated cosolvents used in LHCEs are investigated here in searching for the most suitable diluent for high-concentration electrolytes (HCEs). Nonsolvating solvents (including fluorinated ethers, fluorinated borate, and fluorinated orthoformate) added in HCEs enable the formation of LHCEs with high-concentration solvation structures. However, low-solvating fluorinated carbonate will coordinate with Li⁺ ions and form a second solvation shell or a pseudo-LHCE which diminishes the benefits of LHCE. In addition, it is evident that the diluent has significant influence on the electrode/electrolyte interphases (EEIs) beyond retaining the high-concentration solvation structures. Diluent molecules surrounding the high-concentration clusters could accelerate or decelerate the anion decomposition through coparticipation of diluent decomposition in the EEI formation. The varied interphase features lead to significantly different battery performance. This study points out the importance of diluents and their synergetic effects with the conductive salt and the solvating solvent in designing LHCEs. These systematic comparisons and fundamental insights into LHCEs using different types of fluorinated solvents can guide further development of advanced electrolytes for high-voltage LMBs.

After decades of dormancy since the emergence of lithium (Li)-ion batteries (LIBs) in the early 1990s, Li metal batteries (LMBs) have been revitalized in recent years as one of the most promising electrochemical energy storage systems because of their high energy densities (1–3). Nevertheless, the renaissance of Li metal anodes (LMAs) used in LMBs is still constrained by two critical obstacles: low coulombic efficiency (CE) and high surface Li growth over cycling. In this regard, the electrolyte has been increasingly recognized as one of the most critical components in stabilizing LMAs and regulating Li deposition and growth because it determines the nature of the solid electrolyte interphase (SEI) on LMAs (4, 5). The state-of-the-art (SOA) LiPF₆/carbonate electrolytes tailored to LIB chemistries have demonstrated good ionic conductivity, electrochemical stability, and favorable SEI properties on graphite anodes (6). Although the overarching design goals of an ideal electrolyte remain the same from LIBs to LMBs, Li metal, with an electrochemical potential of −3.040 V vs. the standard hydrogen electrode, is very reactive to the SOA carbonate electrolytes and leads to severe LMA corrosion and electrolyte depletion. It also results in uncontrolled Li dendrite growth and greater safety risks for practical applications (5, 7). To this end, electrolytes beyond SOA carbonate electrolytes are essential to enable longer cycle and calendar lives and higher safety of LMBs. Although ethers are known to be more stable with the LMA than the carbonate solvents, their intrinsic instability against oxidation in regular dilute electrolytes has long hindered their applications beyond 4.0 V vs. Li/Li⁺. However, long cycling stability was recently reported in Li||LiNi_1/3Mn_1/3Co_1/3O₂ (NMC111) cells with a charge cutoff voltage of 4.3 V, where an ether-based highly concentrated electrolyte (HCE) was used (8). The HCE of lithium bis(fluorosulfonyl)imide (LiFSI) in 1,2-dimethoxyethane (DME) at a molar ratio of LiFSI:DME = 1:1.2 could greatly enhance the stability of LMBs with a Ni-rich LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811) cathode at 4.4 and 4.5 V, even under practical conditions (9). In this HCE, the absence of free DME molecules alters the solvation structures of Li⁺ and leads to a salt-derived SEI on the LMA and a stable cathode electrolyte interphase (CEI) on the high-voltage cathode. These stable SEI/CEI layers act as kinetic barriers between the electrolyte and the electrodes and thereby limit the continuous side reactions on both LMA and high-voltage cathode during repeated cycling (9). Yamada’s group also reported superconcentrated LiFSI/dimethyl carbonate (DMC) electrolytes for high-voltage (5 V) graphite||LiNi_0.5Mn_1.5O₄ batteries with good cycling durability and rate capability together with enhanced safety (10).To further advance HCEs, localized high-concentration electrolytes (LHCEs) have been developed by introducing nonsolvating or low-solvating solvents (also called diluents) into HCEs (9, 11–13). The LHCEs not only preserve the favorable solvation structures (highly concentrated coordination clusters) in HCEs but also significantly reduce the overall salt concentration in the electrolyte, which is beneficial for lowering the electrolyte viscosity and cost as well as improving the electrolyte wettability on electrodes and separator. Our group previously investigated the effects of a series of model electrolyte solvents (carbonate, sulfone, phosphate, and ether) for LHCEs and revealed the intrinsic synergistic effects between the salt and the solvent when they coexist on electrode surfaces (14). In this work, we will move to another important component in LHCE, which is diluent. The requirements of a diluent have been given in our previous work (11) and summarized in a review article about HCEs by Yamada et al. (15), which include low viscosity, sufficient electrochemical stability, appropriate permittivity, and coordination property (11, 15). Several hydrofluoroethers (HFEs) that meet the above requirements have been introduced as diluents in different HCEs that are based on different conductive salts and solvating solvents, including bis(2,2,2-trifluoroethyl) ether (BTFE) (11, 13, 16–19), 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) (9, 12), 1H,1H,5H-octafluoropentyl 1,1,2,2-tetrafluoroethyl ether, and 2,2,2-trifluoroethyl 1,1,2,2-tetrafluoroethyl ether (20). The formulated LHCEs successfully improve the cell performance of different battery chemistries, which are mainly enabled by the densely deposited Li underneath the favorable salt-derived SEI chemistry. To reveal the fundamental mechanism behind the merits of using diluents in LHCEs, here we carry out systematic studies on the diluents of the known HFEs (including BTFE and TTE as representatives) and beyond including fluorinated carbonate [bis(2,2,2-trifluoroethyl) carbonate (BTFEC)], fluorinated borate [tri(2,2,2-trifluoroethyl) borate (TFEB)], and fluorinated orthoformate [Tris(2,2,2-trifluoroethyl) orthoformate (TFEO)]. The molecular structures are given in SI Appendix, Fig. S1. Postmortem analyses and theoretical simulations are performed to understand the underlying mechanisms for the varied behaviors in the LHCEs based on different types of diluents. It is evident that the diluent has significant influence on the electrode/electrolyte interphases beyond retaining the high-concentration solvation structures. The high concentration of salt anions present in the primary Li⁺ solvation sheath is not the only key point in LHCEs. The diluent molecules surrounding the high-concentration clusters could accelerate or decelerate the anion decomposition through coparticipation of diluent decomposition in the SEI formation. Chemistry of a different nature is also found in the CEI formed in different diluents-based LHCEs. The varied interphase features eventually lead to significantly different levels of battery performance. This study points out the importance of diluents and their synergetic effects with the conductive salt and the solvating solvent in designing LHCEs. These systematic comparisons and fundamental insights into LHCEs that are based on different types of diluents can guide further development of advanced electrolytes for high-voltage LMBs.     

维生素B6对减轻红霉素胃肠道不良反应的临床随机对照观察

目的：了解维生素B6与红霉素静滴时对减少（减轻）胃肠道不良反应的作用.方法：观察了2007年5月到2009年5月本中心内科感染性疾病应用红霉素治疗的留观患者300例,其中150例加用VitB6为治疗组;150例不加用VitB6为对照组.结果：治疗组不良反应发生率26%,对照组为87%,P〈0.01有显著差异性.结论：VitB6在预防和控制红霉素引起的胃肠道不良反应上,有较好的疗效.     

新入院2型糖尿病病人糖尿病痛苦与自我管理行为的相关性研究

[目的]调查新住院的2型糖尿病病人糖尿病痛苦与自我管理行为现状,并探讨两者的相关性。[方法]采取便利抽样的方法抽取423例新住院的2型糖尿病病人,用中文版糖尿病痛苦量表、中文版糖尿病自我管理行为量表对其进行问卷调查。[结果]423例2型糖尿病病人入院时自我管理行为总分为(39.63±3.43)分,各维度得分由高到低依次为药物、普通饮食、血糖监测、足部护理、运动、特殊饮食;61.9%的2型糖尿病病人存在中等以上糖尿病痛苦;病人糖尿病痛苦总分及各维度得分均与自我管理行为总分及足部护理得分呈负相关(P<0.01),糖尿病痛苦总分及情感负担、生活规律相关痛苦、医生相关痛苦得分均与血糖监测及药物得分呈负相关(P<0.01),糖尿病痛苦总分及情感负担、生活规律相关痛苦得分均与普通饮食得分呈负相关(P<0.05)。[结论]新住院2型糖尿病病人自我管理行为水平较差;糖尿病痛苦程度越低自我管理行为水平越高。临床医护人员应重视对病人进行糖尿病痛苦的筛查,及时进行个体化、系统性、针对性的干预,降低病人的糖尿病痛苦水平,促使其形成良好的自我管理行为,以利于血糖尽快达标。     

我国延续护理的CiteSpace知识图谱可视化分析

目的:分析我国延续护理的研究热点及研究前沿,为我国延续护理的进一步研究提供参考。方法:运用CiteSpace软件对1989年—2019年9月在中国知网(CNKI)期刊数据库收录的关于延续护理的文献进行可视化分析。结果:共纳入452篇文献,发文量总体呈上升趋势,发文量最多作者有6人,各发文4篇,发文量最多的机构是北京大学护理学院,发文9篇。老年慢性病病人及早产儿是研究关注的热点人群;慢性疾病是研究关注的热点疾病,其中脑卒中是研究前沿;互联网技术及医院社区一体化是研究的热点方向,其中微信是研究前沿;效果评价是研究关注的热点。结论:我国延续护理日益受到重视,研究热点多样化,运用互联网技术的延续护理及脑卒中的延续护理是研究前沿。但作者及机构间相互合作较少,尚未形成延续护理核心科研团队,缺乏延续护理的规范化评价标准。     

Value of frontal QRS axis for risk stratification of individuals with prolonged PR interval

Background

There is ongoing controversy regarding the prognostic value of PR prolongation among individuals free of cardiovascular diseases. It is necessary to risk-stratify this population according to other electrocardiographic parameters.

Methods

This study is based on the Third National Health and Nutrition Examination Survey. Cox proportional hazard models were constructed and Kaplan–Meier method was used.

Results

A total of 6188 participants (58.1 ± 13.1 years; 55% women) were included. The median frontal QRS axis of the entire study population was 37° (IQR: 11–60°). PR prolongation was present in 7.6% of the participants, of whom 61.2% had QRS axis ≤37°. In a multivariable-adjusted model, mortality risk was highest in the group with concomitant prolonged PR interval and QRS axis ≤37° (hazard ratio [HR]: 1.20; 95% confidence interval [CI]: 1.04–1.39). In models with similar adjustment where population were reclassified depending on PR prolongation and QRS axis, prolonged PR interval and QRS axis ≤37° was still associated with increased risk of mortality (HR: 1.18; 95% CI: 1.03–1.36) compared with normal PR interval.

Conclusions

QRS axis is an important factor for risk stratification in population with PR prolongation. The extent to which this population with PR prolongation and QRS axis ≤37° is at higher risk of death compared with the population without PR prolongation.     

归肝经中药作用于人肝癌细胞差异表达 蛋白酪氨酸激酶的筛选与分析

目的 应用蛋白芯片技术筛选归肝经中药作用于人肝癌细胞蛋白酪氨酸激酶(PTKs)系统的特征性差异表达蛋白,并分析不同归肝经中药与PTKs调节的差异性.方法 选择40只BALB/C裸小鼠,采用将皮下瘤组织块植入肝左叶实质内的方法复制原位移植瘤模型,模型复制10 d确定成瘤后分为4组,各组分别腹腔注射相应的中药提取物,归肝经化瘀消癥药对组给予三棱和莪术(给药量为含生药4.5 g·kg-1·d-1)、归肝经攻毒散结药对组给予蜈蚣和全蝎(给药量为含生药0.3 g·kg-1·d-1)、归脾经对照药对组给予黄芪和白术(给药量为含生药6.3 g·kg-1·d-1),模型组腹腔注射等量0.9%生理盐水.药物处理3周后处死小鼠取肝癌组织,采用蛋白芯片技术筛选归肝经药对作用于肝癌细胞的差异表达PTKs并进行聚类分析.结果 实验结束后各组动物数分别为化瘀消癥药对组6只,攻毒散结药对组5只,对照药对组5只,模型组7只.蛋白芯片筛选结果显示:以调节倍数大于1.50或小于0.67判定为差异有统计学意义,与模型组比较,化瘀消癥药对组42种表达均为上调〔包括29种受体酪氨酸激酶(RTKs)和13种非受体酪氨酸激酶(nrPTKs)〕,其中调节倍数大于5.0的有促红细胞生成素产生肝细胞受体B1(EphB1)、表皮生长因子受体(ErbB2、ErbB4)等3种RTKs;调节倍数为3.0~5.0的包含7种RTKs,分别为EphA1、EphA3、EphA7、成纤维细胞生长因子受体2-α(FGFR2-α)、肝细胞生长因子受体(HGFR)、巨噬细胞集落刺激因子受体(M-CSFR)、血管内皮细胞生长因子2(VEGFR2);2种nrPTKs分别为非受体酪氨酸激酶BMX(BMX)、Janus激酶(JAK1).攻毒散结药对组表达上调23种(RTKs 15种、nrPTKs 8种),6种下调,其中调节倍数为3.0~5.0的RTKs分别为ErbB4、M-CSFR,1种nrPTKs为巨核细胞相关酪氨酸激酶(MATK).对照药对组表达上调28种,下调8种.聚类分析结果显示,符合筛选条件的PTKs差异表达在化瘀消癥药对组有17种,其中9种RTKs〔受体酪氨酸激酶样孤儿受体(ROR2)、干细胞因子受体(SCFR)、间变性淋巴瘤激酶(ALK)、血小板源性生长因子受体-β(PDGFR-β)、胰岛素样生长因子-IR(IGF-IR)、ErbB2、ErbB3、EphB1、EphA2〕,1种nrPTKs〔fps/fes相关酪氨酸激酶(FER)〕,7种PTKs,包括3种RTKs(M-CSFR、FGFR2-α、EphA3)和4种nrPTKs〔乙酸激酶1(ACK1)、布鲁顿酪氨酸蛋白激酶(Btk)、非受体酪氨酸激酶ABL1(ABL1)、BMX〕;在攻毒散结药对组有7种,包括5种RTKs(M-CSFR、FGFR1、ROR2、EphB1、ErbB2)和2种nrPTKs〔缺乏C端调节与N端烷基化位点的Src相关激酶(SRMS)、FER〕.结论 具有攻毒散结作用的蜈蚣和全蝎药对比具有化瘀消癥作用的三棱和莪术药有更好的抗肝癌作用,其机制可能是通过调节PTKs信号通路.归肝经活血化瘀药对三棱和莪术可能存在独立于PTKs信号系统外的抗肝癌效应途径.     

Complex Rehabilitation for an Adolescent with Ectodermal Dysplasia—A 10‐Year Follow‐Up

Maxillofacial rehabilitation of patients with ectodermal dysplasia (ED) often presents clinical challenges due to hypodontia and hypoplastic alveolar bone. This clinical report describes a 16‐year‐old patient suffering from ED who displayed severe hypodontia, maxillary retrusion and thin knife‐edge alveolar crest. This patient was treated with distraction osteogenesis and a bone graft harvested from the iliac crest to correct maxillary retrusion and bone insufficiency. Six months later, implants were inserted. Then, implant‐supported overdentures were completed. Although a new implant was reinserted during the 10‐year follow‐up, the results showed that combination surgical treatment achieved a predictable, functional and esthetic outcome in a patient suffering from ED.     

阑尾开口炎在远端溃疡性结肠炎的临床意义

目的研究阑尾开口炎(AOI)出现在远端溃疡性结肠炎(DUC)的临床意义。方法从我院炎症性肠病数据库中选择资料完整的DUC伴有AOI和不伴有AOI的患者。两组在病变程度、吸烟史、诊断时年龄、病程及初始治疗药物等进行配对。收集随访中的临床资料,并比较AOI在缓解期及活动期消失的比率。结果 23例患者符合诊断DUC伴AOI,病变位置以乙状结肠和降结肠为主。患者起始使用美沙拉嗪的途径分别为:口服(34.8%),栓剂(13%)、两者联合(52.2%)。随访时间平均为25个月,经使用氨基水杨酸治疗后大部分患者病情控制或缓解。只有2例患者病情加重,病变向近端发展。与31例对照组患者比较,两组在各个临床指标方面没有明显差异。缓解期有66.7%的AOI愈合,而活动期只有25%愈合(P=0.09)。结论阑尾开口炎可能是UC疾病活动的一个标志。作为一个亚组,DUC-AOI疾病预后较好,出现病变加重、需要免疫抑制剂及手术的可能性较低。     

胰岛素样生长因子-I受体异常激活与肝癌靶向治疗

肝细胞恶性转化和癌变过程中,胰岛素样生长因子-I受体（IGF-IR）异常活化。IGF-IR过表达既可作为肝癌早期诊断的标志,又可作为肝癌靶向治疗的新靶点,且具有应用前景。本文对IGF-IR信号通路异常激活及分子靶向治疗肝癌等的研究进展作了综述。     

近十年我国可穿戴设备在健康管理领域的研究现状及发展趋势

背景 随着可穿戴技术的日益成熟，可穿戴设备在健康监测、评估和干预中的应用价值逐步体现，并将助力于健康管理领域的创新发展。目的 分析近10年我国可穿戴设备在健康管理领域的研究热点、前沿和趋势。方法 检索并分析中国知网数据库中2011—2021年主题为“可穿戴”的期刊文献，通过Excel表格分析纳入文献的时序和空间分布，通过CiteSpace软件对文献关键词进行可视化分析。结果 2011—2021年，我国可穿戴设备在健康管理领域的发文量总体呈上升趋势（共519篇），于2021年达到最高（85篇）。纳入文献涉及生物医学、信息科学、计算机硬件和软件技术等多门学科，发表于医学信息学杂志、中国数字医学、智慧健康等多种期刊。发文量排名前3的研究者包括中国人民解放军总医院的张政波教授、上海中医药大学的罗晓兰副教授、中国医学科学院医学信息研究所的何晓琳研究员，发文量排名前3的科研机构分别是华中科技大学（14篇），上海交通大学（10篇）和东南大学（10篇）。反映研究热点的关键词包括“移动医疗”“健康管理”“智慧医疗”等，反映研究前沿的关键词包括“老年人”“糖尿病”和“心律失常”等，反映研究趋势的关键词包括...